Purpose: The growing awareness of climate change, biodiversity loss and the wider global environmental emergency has led to calls for decisive and immediate action from all sections of society. This paper aims to consider the question of how universities should respond and what role they might best adopt in current circumstances. Design/methodology/approach: This paper presents a conceptual framework, the paradox model, which places sustainability within the contradictory, messy and uncertain terrain that characterises higher education (HE). This is derived from the own experience of leading sustainability within one UK university, as well as the continued engagement with educational theory and philosophy. Findings: This paper identifies two fundamental contradictions or paradoxes facing those seeking to engage in sustainability in HE, namely, how to develop authentic sustainability responses within the context of existing HE structures and processes and how to reconcile the demand for immediate action with the much more gradual processes of education. This paper represents these two paradoxes as intersecting axes on a diagram, which creates four quadrants in which a diverse range of responses can be located. The point where these two axes intersect is particularly significant and provides a place from which to navigate responses both individually, collectively and institutionally. Originality/value: This paper argues that wisdom provides a guiding principle for discerning which type of response might be appropriate in any given context. It may also indicate a route towards institutional change and underpin the vision of the ecological university of the future based on principles of civic responsibility and social justice.